The evolution of technologies makes surveying accessible to a broader community of professionals and students. Therefore, teaching geomatics is a continuous challenge. This article presents an original pedagogical approach based on a teaching unit gathering students in architecture, as well as in civil and environmental engineering. Working together to collect and visualize data from the built and natural environment is a very stimulating experience. However it requires multiple competences in data analysis and mapping. At the Ecole Polytechnique Fédérale de Lausanne (EPFL), the Faculté de l'Environnement Naturel, Architectural et Construit (ENAC) has introduced a teaching concept called “Projeter ensemble” which consists in a series of multidisciplinary courses. This paper presents a teaching unit for mapping changes of the natural and built environment, focusing on a project carried out in the antique theatre of Aventicum (now Avenches), which is one of the major Roman settlements in Switzerland. The teaching activity has been proposed for 4 years. During this period, restoration works of the antique theatre have taken place and the archaeological site has been surveyed regularly. Hence it is an excellent opportunity to analyse the evolution of the theatre through the comparison of 3D surface models from different epochs. The students benefit from an exciting field of experiment. They collect real data and build 3D models, which they analyse with adequate software. In this sense, they develop very good skills in data processing and in quality assessment of the mapping products. This teaching unit does not aim at training a few specialists in geomatics. However it contributes towards the critical use of modern mapping tools in widespread domains of activities.